Electbic heating ttwit



' 1,632,318 June 1927' F. c. SIMMS ELECTRIC HEATING UNIT Filed May 29.1925 27 ea-i] 26 1 glTNESSZ:

ATTORNEY lit Patented June 14, 1927.

UNETED STATES 1,632,318 PATENT oFFic FRANK c. snvrms, or EAST PALESTINE,OHIO.

ELECTRIC HEATING UNIT.

Application filed May 29,

, member, of a-dense, hard material that-islieat-and-electric-conducting, and that has a plurality of spaced,alined tubular members of aceramic electricrinsulating material locatedtherein 'to receiveaaresistor member.

' invention,

The tubular -members have enlargedopen ends to receiYe' analining andresistor-protecting member-a.

In the single ,sheetofidrawin' 5,. j'. F igure-1 isfaview, in;ve'rtical.Ongit-udinal; section, of an electric furnace embodying my Fig. 2 is avie -,Iin afiertical"lateral-section, taken on the line I I+II of,Fig.1, .5:

Fi and partially in longitudinal section, of a heating unit embodying myinvention Fig. 4 is an end view there'of,-

Fig. 7 is a. vie\v,;in'; end elevations of-another form f deviceembodyingzniyinvemlLlOIl, 1, ."ttiiii Fig. 8 is aview,ina.side-elevation,-of a locking means,= f Fig. 9- is a;vieW.,-in.section therethrough taken on the; line IXIX.of Fig.i8,j

vention, and, in:

Fig. 11 is a view, in endelevation, thereof. An electric resistancefurnace designated a generally-by the numeral 11in 13 land 2 of thedrawings, comprisesa: plurality .of

bricks or blocks -12".=o'f-a: snitableirefrac'tory; heat-insulatingmaterial, built-.up; to consti-j tute a plurality of Walls enclosinga-furnace chamber 13. While-I have illustrated; a furnace chamberthat-is substantially square in lateral section, I do not Wish to be?restricted thereto, as any desired size and-shape-of fur-- nacechambermaybe employedthereof, with enlarged Y other. However,

3 is a view, partiallyinfsidei elevation Y 1925. SerialNo. 83,585.

A heating means for the furnace comprises a plurality of plates 14,illustrated more particularly in Fig. 3 of the drawings, ofsubstantially rectangular form in both lateral and longitudinalsections. Each member 14 consists of a mass of initially-moistened,comminuted, heat-and-electric-conducting material, such as carborundum,that has been tightly compressed into the desired shape and dimensions.A plurality of alined tu bular' members 15, of ceramicelectric-insulating material, are located within the membet- 14 andextend longitudinally thereof. The members 15 are provided, at each endend portions '16 for a purpose to be hereinafter set: forth in detail. Ipreferably make-the tubular members 15 in one piece, in order that theremay be no joints from one enclthereof to the if the .length'of themember 14 and therefore of the tubular members -15, should become-jtoo'large to permit of manufacturing the members; 15 easily and,economically, I may makethem of two or even. of three piecesabutting-relation.- I a The member 14 isimade in a mold which hasprovision for holding th'etubular memlocated, in alined and ber intheir. proper zoperative positions ,dur- .fl g't em d ng.QPerat O Fig. 5is an end vieW-.-of= ;am0di'fiediforma ,Any; ,desired sequence ofstepsin} the, molding operation may .vide, a -,dense, homogeneousplateofthede- -i.sired;.shape and;.; dimensions, of initially- -;Inoi stened,-cornminuted' V .carborundum ,that is't-ightlycompressed, particularly soaround the tubular membersjeAftendryingout and being heated toarelatively-high. temperature, such plates are relatively; hard and denseand still withstandfconsiderable shock without, breaking or .crackin thetubular sideaelevation, of a. fmembers -15'aiding inrstrengtingtheplate. modified form of .de'vifce embodying my in- --A"resistor.member is located ;within' the .tubular ,ine-mbers- 15 and. extendstherethrough, .and comprises :a relatively heavy and; preformed rod; -wire,-or-bar .o fi a suitabl resistance material, such as; nichrome. Thewireor'rod. is bent'tosubstantially U- form orto hairpin shape, as moreparticularly shown in Fig.1 of the drawings. :Thus eachindividualresistorportion 1sl o cated in two adjacent. tubular members,and adjacent ends of. the resistormembers at one end of the furnace maybe connected by any suitable means, here shown as clamping bars .18.

nace'scruct urev 7 The, end portions of the-upper and lowerresistor-members of hairpin form may be made longer, as indicated at 19and. 2lr re-, spectively in order that they 'may pro ect 5 through onewall of the furnace structure to have suitable supply circuit conductors(not shown) connected thereto. Bushings 22 may be located in the furnacewall to insulate:

the end portions 19 and 21 from the fur- Ifitistlesired toemployannumber of 't-he combined 'muhle' and resistor-supportm -membersle -in" end td'e'nd relafion; itris highly -desirabl that) means beprovided to protectthe resistor i'nember at the joint between the twoabutt-ingmem'eersl ti-Tem- "ploy forthis purposea' r'elatively short'bush- -ing 23;-of"a ceramic electric-insulating ma- "terial, whichfits'into theenlarged end por- ""23 not-only i b'eztfifemabtittihg 1 members14, buti also at the endfiioi'tions thereof where heating units inFig;-Pblf theidra wings the fiirnaeeehember,i* fis' ill'iistrzited insupporting-members; is con'stit-utedby rela wherein tubular members27,-0f flattenedot" mpl'o'y eld" 'for ihbltitliig the member Ii -in=-'These mem relation -to= constitute a? mufile' that is substant-iallycircular in outlines ovaL shape in lateral section, are employed insteadofthc circularfmembers 15. This permits of the use of ribbon instead ofthe .hereinbefore described wire or rod.

'Fig. 6 illustrates another modification in whicb a member 29 that ismade in the same manner as the member ll. has located therein aplurality-'of':tubular members 31 of oval shape in lateral section, thelonger dimension thereof being aliued' with the plane of the member '29.This form of flattened tubular member permits of using a resistor ribboni nstoad of -a baror rod andit is .tobe noted that the greater surfaceofithe resistor-member is alined with-the surfaces of tiieunember 29."Both 1 forms I of resistor supporting andmutll'e= plate membersillustrated in Figs: 5 and 6 permit of translatinga greater amount of:electric cnergyint-o heat, than is the case in -the"form illustrated'EinFig.

'4.-' The tubular members-may be 'located closer to 'one'sideof-the'=plateth an to the oth'er, in orde'iz th'at -the'resistorniembers m'ay-be located closer to the ch'anrbenthan;

to= the wall M ths-furnace; the deng'tli o'f the heat path into' thechamber'beiiig thereby shortened "and the' thermal 'resistance againstthe fiow 'ofi heat into the furnace wall being somewhat increasedL formthan is the case when theiorms'illusthis may ordinarily no ti'lie' ofimportatrzce,

mnige'e, I' fhay provide is: hot restriete'd to a plzine and":rectangular form, but it may also be made in an-y otzher suit-able or'desirecl form; such= as the .arc'uate form iHUstI atecP in -FigL 7 A;member-'32- is there illustrated' as being of areuateiforin, in endelevation; and 'bein'g otherwiseio t substantially rectangular contours:"A' plura'lity =-of= tubular-:memhers' 3350f ceramic, electric insulating imaterimtiiare located in Mined- 11ml spaced relation within 5 themember -32, and extend longitudinally I thereof. am e kindfiof Themember 32 is made of carbornmh-nu.that jf'niateria' asjthe rnemb'ers lor as the tubes -'is' initially .1noistened 1 andvis' vcompreese' d un15. i Eclfieornefl'ofthe "members PE is pre de!- greatvpressurewindhis'then heated" to a v'idediwi'th smal l r'ejcessf26 tfltatis' ofsuch high temperature:stodryoot jall moisture ShApe EisijoWetiiXePa p0i'tion==of"-th'e"mem contain'edi thereinr 3 7 .41 i

'b'er '2-5f Whenib'iitf members "l t areto 5 be' "The form of mullle'plate illustrated in loc ated in ite positions shown i'Ii' -'Fig lfFi'g."9 ie is ori'ly'ineee'sser to alining rne'fnb'ers" 2 5 that' ofp'eratiiiely engages" a corner -oi-eac'h"of-1he fonr members. I

5illustrates].a modified form iof eon :struc't i'on of a'yiesistorsuppo'rting membei clmvature offleaclrofthe-muifie plates must:

1 arcuate 'members' 32 are :locatedinabutting Themadius of of'course, bemade-. such/ -that:a chamber of Y i 7 may be employed in vertieal shaftemplo "one of the 'furnacesfinwhichi case a plurality of the lllt) shownin Fig. 11.

the desired diameter is obtained.- Any desired number of mufile platesmay be located in superposed relation, in order to provide afurnace.chamber of the desired height. The muflie plate 32 may also be employedin a horizontal shaft furnace to surround a furnace chamber ofsubstantially circular shape and extending longitudinally. Recesses 26are provided at each corner of the plates 27, 29, and 32 toreceive'alining members25. The ends of the respective tubular members28, 31, and 33 are provided with enlarged end portions, as washereinbefore described in connection with the members 15. Co-operatingresistor-protecting and alining members 23 or similar thereto are to beemployed whenever two of the plates are located in abutting relation,and also at the outside ends of the plates.

Figs. and 11 illustrate another modification wherein provision is madefor locating a resistor member at the joint between two muffle plates.To this end I provide a substantially semi-circular groove in the edgefaces andlocate therein a tubular member for receiving a resistor. Aplate 34 is built up in substantially the same manner and of the' samekind'of materials as was hereinbefore-described for the plate 14. A

plurality of tubular. members 35 are located within the body'of the;plate andare of the same kind of material and construction as thetubular members-; 'The edge faces thereof are 'provided-r,-withisemi-circular "grooves 36 and 'a tubular' member 37 is located I within"the circular: groove,; formed when two of the members 34 are locatedwith their edge faces in abutting relation," as

The tubular members may be-bfi tl'ie same general formas -washereinbefore described in connection with the members 15, thatisthey'may be of one pieceandi have enlarged; outer' ends to receive analining and protecting member 23. I may alsomake the j members '35shorter} than the length of one block and have the abuttingends thereoflocated in a short tubular member 38.25 a! The tubular members- 37 and38 are to be inserted between successive superposed plates 34-as theyarelocated their proper operative positions in the-furnace structure. lThese tubular members will ensure-avertical 'alinement of the mufiieplates,'but I= may provide additional means for maintaining the platesin alinement by a tongue and groove connection -therebetween, Iasindicated by the numeral 39 in Fig. 11.

The plates 34 are alined longitudinally thereof by the members 23inserted-in the enlarged ends of the tubular members 37.

If tubular members 31, of ovalsection, are employed (similar to thoseshown in Figjfi) and are located closer to one surface of the beprovided in-the corners, in the same manner and for the same purpose ashereinbefore explained.

The deviceembodying my invention provides a form of combinedimuflleplate and 'the: use of the mufiie plate einbodying my :7

invention-is efi'ectivcain protecting the resistormember while at; thesame :time permitting' of operatingfithe resistor: at relativelyhighjtemperatures without danger of unconfined: distortion itliereofwhich might otherwise cause eitliershort circuits between "adjacentportions-ofrthe resistor member, or grounds :between- :the resistor-andmetal portions of Y the furnace structure. Where it desirable to have asubstantially;:uuiform distribution of heat/ovenithefientire. surfaceaaofitheimufilel plateiuthisfz'may 'lbc efl'ected by theuseofitheimodification illustrated in Fig. 6' ofithdi'awingst bllt'is.possible 20f course 3 to locatei the tub ular Fmerhtiers-nl-osen-tdgethe 1" th an fitherezish'owmi whereby the heat distribution overtthe Fsurface 'iofr the. plate 'will be substantiallyiruni'formmi a'im lum'i''1 hei -iiesistdnmienihers lcat'edrinthe tubular hiembers maymperatelatairelatively high -teinperaturei andithezntirel plate iwill reach '21:relati-velyuliigh .fieiiiperature .tha'tv -will besubstantiallyiunifominoven the; surface of the lplatea mthilinz'wilhltherefore, constitiitei a :saurce e'f'uniformly distnibuted;heat-.-

m While theiheat' generated-fin; the individual resistbr p'ortionslocated in the tubular mem- :bersg will: bersubstantially uniformalaterally ..-ofi the-resistou' members or inii'a direction of-the-rz'thiclmess:ofthewplate, the heat-that is transmitted to-:the:s'urface of.the gnufile plate Elocatedi adjacentitoi'aiwalliefytlr'e furnace is conductedntoithemther'zsua'facerof the plate byreasoIi-ofifthe .factthatitbe .highly. compressed carborundume is; an 1excellent conductor of heat. This prevents, to a great extent anyzacciunulatioir of-:heat onthat side .of the; plate away from the furnacechamber. The ceramio tubulangmembers 15. 28, 31.

and 32 will serve also? as 2a means for strengthening: theiplate:withwhich they are respectively associatedmThis: will be espec iallytrue of the members, 31, and a muiile --pla,te embodying; my inventionis especially platethan to the other, the recesses 26mayladapted'towithstand hard ,usage in a fur Lil "tireilengt hltire 4:lni'anielectricr'furnaoe, in a' pluralityof "mufile zindresistorfisupporting nace incident to placing materiat-in or removingzit fromthefurnace chamber.

lVhile I have illustrated certainuspecific embodiments ofizmyxinventionIxdo not-dc sire to belimited :-thereto,'- but" intend thatpluralityoi'tubular 'memben; of ceramic electric-insulating material,-in saidplate for remova-bly receiving: a resistor-member;

' 3. A; combined muffle amlresistor-support,

comprisinga' plate-"- of ziniflatly-moistened, compressed,comminnted:earborundum, and

anpluralit y' of tubes "ofrefnactory' electricinsulating.ninterial-locatedtin said plate for n v p receiving aresistor membertherein. and =for corering thesame over;substantially.- its encombination,

membersdocated inrabuttingarel'at'ionya plurality ':of spaced; aliridtubes/ft electric-5nsrilating:anaterialalocatedl I insjeacha of said =rnem'bers, and-means intenfitting-i-ivit-h the adjacent ends-of'saidatubesiforlholdi'ng. said muttle members inna' lineinnntiinimumak l5. A1; combined-i muflleaizmda f resrstor 'supportyieomprisinglaehardgcdense platewf ini- 'tially moisteiiedp' Irefractoryn; heat-and -electrio-conducting materiel-1!, and i aplurality of tubular r'esistor recervan memljers',=. of electri'c'iris'ulating' maberial iiinsaidfiplate; each member embodying meansafdneffecting.- a

1 greater i creeping distance: between: a? resistor therein and theplate= abl t-he-iends thereof, than the direct distance 'betweeni saidparts. 6. Inan electric furnace,- in combi-nati'on, a pluralityofformed' refraetory. resistorsupporting plates; of substantiallyreetangm lanform located in abuttingmelation and a single meansint-erfittfing withiaiid extending into 'a cornerportion may ofthe='abutting plates formaintaining tl'iern alinement. i ii an, anelectric fuma'ceyim combination, a plurality of formed'refract-oryplates of a hard, dense, heat-and-electric-conducting material locatedin abutting eiid-to-end 'relati'on, apluralityof tubularmembers',-of-electrio-insulating materialzhaving enlarged endportions,-located'-in spaced and alined positions insaid'respective=plates,- and means interfitting, with- -the adjacentenlargedend portions of said tubular members formaintainingsaid platcsinalinement relatively to each other.

S'. A Combined mutlle and resistor support, comprising a hard, densemember of redetermined form and of heat-and-electric-conductingmalcriah. and a plurality of spaced, :ilincd tubiilarmemhers, of ceramicelectricinsuint-ing: material, located in said member few-receiving andsupporting a resistor memher extending through said resistor support inthe plan-e thereof.

5). In an electric furnac the combination with aplur'ality'ot' wallsenclosing a furnace chamber-ct predetermined form, of a combined muland'resistor-supporting member therein: conforming; to a portionofnoneof sir-ii! walls aadwsupportcd adjacent thereto, and membercomprising a plateof highly ('nlnpi'esscd,her.t-nnd-electric-conductingmai'erial-aml a plurality of tubularmembers of ref-ractor v elect c-insulating material, .exterating i121!ally 'therethrough: for receiringa-i szsrorrnemberz; l0. d1 ctmihined,in'utlleplate andresistorppm-t, comprising a removable plates-0finitially-coniminated compressed heatand- ,ei r-ccnduct-ing:material,and electric-insulating; lneanszwi'thin said plate forreceiv- 1trigsupporting; member located: therein and forstrengthening--said--plate. v-

;1'1. A-icombinedmutlleiplate and-resistorsupport;comprisingLa formedplate of-heat- -'.c'ondiicting.material, and tubular, electric-in--sulating-y -means within said, vp1ate.--.:for {strengthening-the sameand' for removably a-eceivingm resistor member'and for protecting thesame over substantiallyiitsmntire zl tillgtlh'h 5 r I l-Q-xlh:combinedniufile plate and resistorsupport, comprising. a formed plateof=heat- ==conductings inateriah. amt-tubular,- electriclinsulatring,.means within saidzplate for --stren'gt-hening.= the same, and --forrembvably receiving-a resistor memberand for: protect- '2 ing; the-:sameoverisubs'tantially its entire length, said"tubular-means being locatedcloser to one-surface of the plate than tothe 'other.- 1 a In anelectric iurnace,-in combination, a'plurality of formed refractoryplates: ofi-ia dense heat-and electric-conducting material located withtheir edgeface's in abuttingrelation, each edge face ha ringfa'gi'ootc'therein; anda tubular member, of refractoryelectric-insulating; material, locatedin the grooves ini theFedge faces.for receivinga I "resistor member: and for maintaining'said plates sinalin'emenL- In testimony whereof, I- have hereunto subscribed my namethis 26th day of May, 1925;

FRANK c. srMMs,

and: protecting; a resistor

